Grass family (Poaceae)
Description: This native perennial grass is ¾2¾' tall and develops tufts of unbranched leafy culms. In sunny habitats, this grass is taller and more stout, while in shaded habitats it is shorter and more delicate. The culms are light green, slender, and glabrous. About 6-8 alternate leaves occur along the length of each culm. The leaf blades are 1-6 mm. across and 2-10" long; they are medium green and hairless. The leaf sheaths are medium green, hairless, and open. At the junction of each blade and sheath, there is a ligule that is white and membranous. The nodes along each culm are green and swollen.
The culm of each fertile shoot terminates in an inflorescence about 3-12" long and half as much across; this inflorescence is often as long as the rest of the shoot. It consists of an airy panicle spikelets that is much branched. The rachis (or central axis) of this panicle is slender, hairless, and tends to zigzag along its length between whorls of 2-3 branches. Terminal branchlets with spikelets often develop toward the middle of larger branches; these branches are usually quite divergent, especially for fertile shoots growing in shaded habitats. Each spikelet consists of a pair of glumes and a single lemma with a floret; the inner palea is absent or insignificant. The glumes are 2-3 mm. long, light green, lanceolate, and strongly keeled; one glume is slightly larger than the other. The lemma is 1-2 mm. long, light green, and oblong-ovate; it is shorter than the glumes. In each spikelet, the prominent glumes resemble a pair of tiny claws. The blooming period usually occurs during the late summer or early fall. Pollination is by wind. The inflorescence turns tan when the grains ripen. The root system is fibrous. Sometimes, this grass forms small colonies by reseeding itself.
Cultivation: This grass can adapt to a fairly broad range of growing conditions. It tolerates full sun to light shade, moist to dry conditions, and soil containing loam, clay loam, and rocky material. For a cool-season grass with a C3 metabolism, it is slow to develop as most vegetative growth occurs during the summer, rather than the spring.
Range & Habitat: Upland Bent is common in southern Illinois, occasional in central Illinois, and uncommon or absent in the northern part of the state. Habitats include rocky upland woodlands, mesic woodlands, thinly wooded bluffs, wooded slopes, woodland openings, prairie swales, dolomite prairies (in NE Illinois), and gravelly seeps. In woodlands, this species is often found on decayed tree stumps or near the base of deciduous trees. In sunny habitats, where it is less common, this grass prefers areas with more ground moisture. The size and appearance of Upland Bent is highly variable across different habitats.
Faunal Associations: Little information is currently available about floral-faunal relationships for Agrostis spp. (Bent Grasses). The caterpillars of the following skippers are known to feed on the foliage of Bent Grasses, although not exclusively: Amblyscirtes vialis (Common Roadside Skipper), Hesperia leonardus (Leonard's Skipper), and Hylephila phyleus (Fiery Skipper). Another insect that feeds on Bent Grasses is Chaetocnema denticulata (Toothed Flea Beetle). Bent Grasses are palatable to many mammalian herbivores and readily eaten by horses and livestock.
Photographic Location: A decayed tree stump in Busey Woods, Urbana, Illinois. Toward the middle of the above photograph, there is a light green leafhopper perched on one of the stems.
Comments: This is a rather ordinary-looking grass that blooms during the latter part of the growing season. Upland Bent and other Agrostis spp. (Bent Grasses) have small delicate spikelets; each one with 2 prominent glumes and a smaller lemma. The spikelets of some Bent Grasses have an inner palea near the lemma (which is hard to see), while Upland Bent lacks this structure. Unlike some other species in this genus, Upland Bent also lacks awns on its lemmas. Two similar species, Agrostis hyemalis (Tickle Grass) and Agrostis scabra (Rough Tickle Grass), have terminal branchlets of spikelets toward the tips of the larger branches. In contrast, Upland Bent has some branchlets of spikelets toward the middle of the larger branches, and the branching pattern of its panicles is often more divergent. Another common name for this species is Autumn Bent.